This invention relates to a portable label printing system and, more particularly, to a portable label printing system having a particularly light and therefore easier to handle data inputting unit.
Conventional, electronically-controlled, portable label printing systems have been in use for entering into the system merchandise related information that is thereafter imprinted on labels suitable for being attached to merchandise or the like. One typical system of this type is constituted of two selfcontained units including a label printer/applicator unit and a data inputting unit. Label related information is entered into the data inputting unit and the labels are printed and applied by the label printer/applicator unit.
Invariably, a thermal print head is used in the label printer unit because thermal print heads are light, compact and easy to service and maintain. But thermal print heads also have disadvantages One is that they consume more power. Consequently, the typical power supply for a thermal print head is heavy. Thus, the incorporation of the power supply in the label printer/applicator unit of the system results in a printer/applicator unit which is heavier and more difficult to use.
The prior art's solution has been to locate the power supply externally of the label printer/applicator unit, in the self-contained data input unit of the system.
The typical prior art label printing system is illustrated in FIG. 3 and is seen to include an, electronically-controlled, portable label printer/applicator unit 2 and a data input unit 3, the two units being connected to one another by cable 4. For brevity, the label printer/applicator unit 2 will be referred to from here on as "the printer unit", even though the unit 2 is also used for applying printed labels to merchandise. Similarly, the data input unit 3 will be referred to more simply as the "input unit 3".
Information to be imprinted on labels is inputted by means of input unit 3 which unit is conveniently portable and sized to be held and operated with one hand and to be carried in one's pockets or the like. The typical input unit 3 includes an input unit interface 6, an input unit control circuit 7 having a RAM data memory and a ROM program memory, a rechargeable battery 8 for powering the entire system, an input unit keyboard 9, a power switch, operational keys 10 including transmission and function keys, auxiliary switches, and a liquid-crystal display 11 for displaying input data thereon.
Electrical power and label printing information are supplied from input unit 3 to printer unit 2 via cable 4, the cable 4 mating with connectors 5 and 31 of units 3 and 2, respectively.
Printer unit 2 includes a label printing section 13, a grip 2 and a label roll holding section 14. Printed labels are discharged from the label printing section 13 to be affixed to articles by means of label applicator roller 15. The interior of printer unit 3 may be accessed by uncovering the bottom cover 17 through actuation of the open/close button 16.
A roll of thermal labels R, which is usually mounted in label roll holder section 14, consists of a continuous thermal label strip T that is wound into a roll. As illustrated in FIG. 4, the thermal label strip T is constituted of a backing sheet S that is coated with a separating agent and which has a plurality of adherable labels L which are detachably connected to the backing sheet S one behind the other. Information in the form of a bar code B, alphanumeric data or the like which specifies, for example, a merchandise code, a manufacturer's code, a department code, a price or similar information I is imprinted on the labels L. The holes D on the backing sheet S, adjacent the labels L, permit detection of the exact position of the labels. Suitable marks as for example eye marks or the like may be printed on the reverse side of the backing sheet S for enabling positioning of the backing sheet S in the printer unit 2.
The label strip T is fed from thermal label roll R into a label strip passage 19 and past a position sensor 18 The strip T is guided via guide rollers 20 toward thermal print head 21 and a platen 22. At the print head 21, the labels L are imprinted with information which is inputted from the input unit 2. Immediately past the print head 21, the backing sheet S is bent sharply around bending pin 23, in a manner which causes the labels L to peel off backing sheet S. The leading end of the backing sheet S (from which the labels have been peeled off) is guided by guide roller 24 toward a pair of transport rollers 25 which pull backing sheet S and guide it out of label printing applicator unit 13. The peeling of the labels L from backing sheet S is assisted by an auxiliary pin 26 located forward of the bending pin 23. Auxiliary pin 26 assures prompt peeling even of labels L which adhere tenaciously to backing sheet S
Motive power for moving the strip S through the printer is supplied by stepping motor 27 which drives one of the pair of transport rollers 25 through timing belt 28. The stepping motor 27 is driven stepwise and at a rate that conveys and sequentially positions the labels such as to permit them to be imprinted with the proper information.
Label printer unit 2 is electronically-controlled by control circuit 30 which contains RAM data memory and ROM program memory. Power and input information, as noted above, is received through cable 4 via connector 31, the input information being routed through interface unit 32. The control circuit 30 is coupled to: interface circuit 32; position sensor 18; thermal print head 21; stepping motor 27; and operating switch 33. Thus, the control circuit 30 exercises overall control over the functioning of the entire printer unit. Usually, an operator actuates operating switch 33 to start and continue a printing cycle.
Typically, data to be imprinted is inputted via the keyboard 9 of input unit 3, stored temporarily in the RAM data memory of that unit and thereafter transferred to the printer unit 2 via cable 4.
Subsequently, operating switch 33 of printer unit 2 is depressed. This causes thermal strip T to be moved forwardly by transport rollers 25 and information to be imprinted on labels L at thermal print head 21. Immediately beyond thermal print head 21, backing sheet S is redirected around bending pin 23, causing labels L to peel off backing sheet S and to emerge beneath application roller 15. The application roller 15 aids in applying the printed labels to items of merchandise or the like.
One key point to note is that the prior art lightens the printer unit 2 by locating the relatively heavy battery 8 in the input unit 3. While this facilitates use of the printer unit 2, the transfer of the battery to the input unit 3 creates other problems.
For example, the printer unit 2 is typically carried in one pocket and the input unit 3 in another. Initially, the input unit is retrieved and held in the left hand while data is entered with the right hand by means of keyboard 9. Next the input unit is replaced in its pocket and the printer unit 2 is withdrawn from the other pocket and the switch 33 is actuated. This causes labels L to be imprinted with information and to emerge at applicator roller 15. Printer unit 2 is then manipulated as needed to apply the labels L to articles. The process requires too many hand manipulations. The overall efficiency of the label printing and applying process is therefore less than satisfactory.